Making Check boxes act like radio buttons

Check boxes: One called approved and one called denied.
What's wrong with this script?

// assume the on value is 1 and the off value is 0
if (this.rawValue == "1")
{
Approved.rawValue = "0"
}

I get en error on the "{". I have this same script in another file and it works just fine. Why doesn't it work in this form?